Safety and efficacy of blood transfusions are especially important to patients who undergo surgery on an elective basis, because frequently, this is the only time they will be exposed to blood transfusions in their lifetime. The overall goal is to use an existing database to develop important questions about current blood transfusion requirements for elective surgery patients. An existing electronic database includes 7394 patients who underwent elective surgery in one of 7 hospitals during 1987- 1991 in the USA. (The hospitals are located in the East, West and Midwest). This database is unique. It includes common procedures such as hip or knee replacement, coronary artery bypass, aortic aneurysm repair, radial prostatectomy, heart valve replacement, colectomy and others. The Specific Aims are to develop quality assurance methods to: (1) determine the number of units of blood which should be quickly available for specific surgical procedures, (2) determine whether transfusion practices have improved since 1974, (3) determine the efficacy of patients donating their own blood in terms of avoiding transfusion with allogeneic blood, (40 determine the number of units which should be donated by patients, (50 determine the percent of donated units which are wasted, (6) determine the amount of blood loss for surgical procedures, (7) determine whether allogeneic blood transfusion prolongs patients' hospital stay, (8) determine whether th same criteria are used to transfuse autologous, homologous and directed donor blood, and (9) whether 1990 legislation in California improved transfusion practice. Methods and tables from this proposal will serve as Quality Improvement (control or assurance) Standards for transfusion practices.